RingBuffer

////// 变长的RingBuffer///private class RingBuffer{byte[] _buffer;int _read;int _write;int _count;//有效数据长度////// 缓存区总长度//////protected int length{get{lock ( this . _buffer . SyncRoot ){return this . _buffer . Length;}}}////// 存有的数据数量//////public int Count{get{return this . _count;}}public RingBuffer ( int size ){this . _buffer = new byte [ size ];this . _read = 0;this . _write = 0;}public bool IsEmpty ( ){lock ( this . _buffer . SyncRoot ){return this . Count == 0;}}public void Push ( byte element ){lock ( this . _buffer . SyncRoot ){if ( this . willFull ( 1 ) ){this . expendBuffer ( 1 );}{this . _buffer [ this . _write ] = element;this . _write = ( this . _write + 1 ) % this . length;this . _count++;}}}public void Push ( byte [ ] elements ){lock ( this . _buffer . SyncRoot ){if ( this . willFull ( elements . Length ) ){this . expendBuffer ( elements . Length );}if ( this . _write + elements . Length > this . length ){//需要循环写入//1、把尾部的剩余空间写满int tailWriteLength = this . length - this . _write;Buffer . BlockCopy ( elements , 0 , this . _buffer , this . _write , tailWriteLength );//2、从头开始写完剩下的部分int headWriteLength = elements . Length - tailWriteLength;Buffer . BlockCopy ( elements , tailWriteLength , this . _buffer , 0 , headWriteLength );this . _write = headWriteLength;}else{Buffer . BlockCopy ( elements , 0 , this . _buffer , this . _write , elements . Length );this . _write += elements . Length;}this . _count += elements . Length;}}public byte Top ( ){lock ( this . _buffer . SyncRoot ){if ( this.Count < 1 )throw new ArgumentOutOfRangeException ( );return this . _buffer [ this . _read ];}}public byte [ ] Top ( int size ){lock ( this . _buffer . SyncRoot ){if ( size > this . Count )throw new ArgumentOutOfRangeException ( );byte [ ] result = new byte [ size ];if ( this . _read + size > this . length ){//越界了，需要分两段读取//1、把尾部的剩余空间读完int tailReadLength = this . length - this . _read;Buffer . BlockCopy ( this . _buffer , this . _read , result , 0 , tailReadLength );//2、从头开始读完剩下的部分int headReadLength = size - tailReadLength;Buffer . BlockCopy ( this . _buffer , 0 , result , tailReadLength , headReadLength );}else{Buffer . BlockCopy ( this . _buffer , this . _read , result , 0 , size );}return result;}}public byte Pop ( ){lock ( this . _buffer . SyncRoot ){this . _count--;this . _read = ( this . _read + 1 ) % this . length;return this . Top();}}public byte [ ] Pop ( int size ){byte [ ] result = this . Top ( size );//Pop和Top的区别只是Pop会移动起点的位置this . _count -= size;this . _read = ( this . _read + size ) % this . length;return result;}public bool IsFull ( ){lock ( this . _buffer . SyncRoot ){return this . Count == this . length;}}protected bool willFull ( int newDataSize ){lock ( this . _buffer . SyncRoot ){//已有的数据+新的数据长度已经溢出return newDataSize + this . Count > this . length;}}protected void expendBuffer ( int newDataSize ){lock(this._buffer.SyncRoot){    byte [ ] oldBuffer = this . _buffer;    //最优的buffer长度应该是2的指数倍    int expendPows =( int ) Math . Log ( oldBuffer . Length + newDataSize , 2 ) + 1;    int expendSize = ( int ) Math . Pow ( 2 , expendPows );    this . _buffer = new byte [ expendSize ];    Buffer . BlockCopy ( oldBuffer , 0 , this . _buffer , 0 , oldBuffer . Length );}}}